The present invention relates to elevator control during an elevator modernization project. In particular, it relates to dispatching of existing and new elevators in response to hall calls during an elevator modernization project.
During elevator modernization projects in occupied buildings, individual elevators are taken out of service and are upgraded to more modern equipment. This modernization typically includes the installation of a new elevator controller, and may also include a new car operating panel and a new wiring interface to the car controller.
As modernization of each car is completed, it is placed back into service, and another car is taken out of service to be modernized. Thus, during the modernization project, two groups of elevators will be in operation: the new group of elevators that have been upgraded, and an existing group of elevators that have not yet been upgraded. The two groups typically involve control systems that are not compatible with one another, and may be from different manufacturers. During the modernization process, coordination of the new and the existing elevator control systems is desirable, so that both systems are not responding to the same hall calls.
One approach to the dispatching of elevators during elevator modernization is described in the Boyce et al. U.S. Pat. No. 5,357,064 entitled ELEVATOR HALL CALL CROSS-CANCELLATION DEVICE. This cross-cancellation device operates with old elevator controllers that use relay logic to store the hall calls in a memory device. The new car controller can read the hall call memory through the cross-cancellation device. In this way, the new car controller can respond to calls that the existing car controller has not yet answered.
With elevator modernization projects that are now taking place, there is a need to modernize early microprocessor based elevator control systems. These systems do not include the relay logic for storing hall calls that was present in earlier elevator control systems, and which were utilized to perform the cross-cancellation function during modernization. In addition, there is a continuing need to reduce cost and to provide optimal elevator service during modernization projects.